EP2732946A1 - Composite, component therefrom and method for producing the same - Google Patents

Abstract

Composite comprises glass fiber roving in which glass fibers extend in filaments of roving in a main direction, and a thermoplastic material as a matrix. The roving is non-woven, braided or knitted. The roving is spread into individual filaments, at least after mixing with the thermoplastic material. Independent claims are also included for: (1) a composite material comprising at least two layers of composite, in which at least one of the layers comprises the above composite; (2) a component comprising at least one layer made of the composite or the composite material, preferably a composite multilayer material, where the composite or the composite material forms the outer layer; (3) producing the composite, comprising (a) providing the glass fiber roving, preferably a continuous glass fiber roving, (b) applying the thermoplastic material on the glass fiber roving using an extruder, (c) rolling the glass fiber roving coated with the thermoplastic material, for distributing the thermoplastic material, spreading the roving into individual filaments and obtaining a precursor, and (e) hardening the rolled precursor to obtain the composite; and (4) producing the composite material, comprising placing the further layer of the composite in the form of plates, on the precursor, and curing the precursor with the plates.

Description

The present invention relates in a first aspect composites with Glasfaserrovings and thermoplastic as a matrix. In a further aspect, the present invention is directed to composite materials and components with composite according to the invention. Finally, in a further aspect, the invention is directed to a process for the preparation of such composites according to the invention.

State of the art

Composites and composites are materials of two or more bonded materials. The connection is made by material or positive connection or a combination of both. A subset of composites are fiber composites, which generally consist of two major components, namely a bedding matrix and reinforcing fibers. By mutual interactions of the two components of this material receives higher quality properties than each of the two individually involved components. Usually, a corresponding fiber composite material has a fiber direction of the fibers. In this fiber direction a much greater strength than the same material in another form. The general principle is that the thinner the fiber, the greater its strength. Fiber composites are characterized by a high specific strength, ie a good relationship between strength and weight. Typically, sufficient strength is used in various directions rather than individual fibers, fabrics or scrims made prior to contact with the matrix.

Conventional fiber composites of carbon fiber or glass fiber are therefore made of fiber mats or fiber fabrics or knitted fabrics with a corresponding matrix. Duromers with their corresponding subgroups of thermosets, elastomers and thermoplastics can be used as the matrix.

For the production of appropriate composites and fiber composites, there are currently various methods. For laminate production, in which semi-finished fiber products with different main fiber directions are superposed, find hand laying, pre-preg technologies or vacuum infusion application. This semi-finished fiber products in the form of fabrics, knitted or fiber mats are placed in a mold and then soaked with the matrix. In pre-preg technology pre-impregnated fiber mats are used with matrix material. These are then cured by heating.

Furthermore, there is the fiber spraying, here endless fibers are cut with a cutter to a desired length and brought together with resin and with appropriate devices in the mold.

Semi-finished products made of reinforcing fibers impregnated with a plastic matrix are understood as fiber-matrix semi-finished products. Thermoplastic and thermoplastic plastics are used as the matrix. Reinforcing fibers are usually glass fibers or carbon fibers. Pre-pregs are their most well-known representatives, this is usually a semi-finished product made of continuous fibers. For the production of special processes are necessary because the thermoplastic melt difficult because of their high viscosity micro-restriction. Usually, the continuous fibers are used in the form of mats, fabrics or knitted fabrics. Plate-shaped thermoplastic pre-pregs are also referred to as organic sheets.

E-glass fibers are used today as glass fibers. These are used accordingly as mats, scrims or fabrics with thermosets and thermoplastics. From the DE 195 27 154 Thermoplastic deformable composites are known. The DE 41 12 129 A1 describes high tensile strength undirectional composites and methods of making same.

Object of the present invention is to provide composites that are easy to produce and inexpensive to produce over known composites. Advantageous are those composites which show a lower weight per unit area with the same or better strength values compared to known composites and composite materials.

Description of the invention

The above objects are achieved with a composite according to the invention. The composite according to the invention is one with Glasfaserrovings and a thermoplastic matrix, wherein the glass fibers of the roving run in a main direction, characterized in that the rovings in the composite are not woven, braided or knitted and the roving at least after the addition of the thermoplastic in individual fibers was spread.

In the present case, the terms "fiber" and "filament" are used interchangeably.

In the present case, the term "composite" is understood to mean a single-layer element with glass fibers as the reinforcing fiber and thermoplastic as the matrix.

By the term "composite material" is meant an at least two-ply material, wherein at least one ply is a composite.

In one embodiment, the rovings can be present in such a way, that they are essentially parallel in the composite. The rovings are guided parallel to each other and the thermoplastic applied to obtain a precursor. Usually, the roving is coated in advance during its manufacture with a size to achieve appropriate strength and connectivity to the matrix. The matrix is brought into contact with the parallel guided rovings, and by suitable means, such as rolling and calendering, the roving and matrix are brought into the desired shape. The individual roving is spread during the coating with the thermoplastic. Optionally, a spreading can also be done in advance, in order to achieve a better wetting of the filaments and fibers with the matrix. It is preferred that an end spread is achieved during or after the coating with the thermoplastic in order subsequently to obtain a composite according to the invention by curing the thermoplastic. It is preferable that, according to the manufacturing method of the composite, the roving-forming glass fibers are singly present, and these separated glass fibers are substantially parallel in the main fiber direction.

Suitable glass fiber rovings are those of a type of glass fiber or of different types of glass fibers, optionally in combination with other fibers. The glass fiber rovings can be made of e-glass. However, the glass fiber rovings are preferably made of ECR glass. Preferred ECR glasses are those having 1200, but especially 2400 and 4800 tex.

The reinforcing fiber in the composite, in particular an ECR glass reinforcing fiber in the form of rovings, is present in stretched form. It is preferred that exactly parallel reinforcing fibers be used.

The composite according to the invention is preferably one with one in which the matrix in the form of a thermoplastic is selected from polyolefin, polyamide, polylactate, polymethyl methacrylate, polycarbonate, polyethylene terephthalate, polystyrene, polyether ketone, and polyvinyl chloride. Preference is given to polyolefins, in particular polyethylene and polypropylene, as well as polyamides used.

The composite according to the invention is one which has a thickness of at most 1 mm, preferably it is one with a thickness of up to 0.7 mm, in particular up to 0.5 mm in thickness, such as. B. up to 0.3 mm thick. The minimum thickness should be z. 0.25 mm (for example, if the glass fiber content of the composite is at least 50% by weight).

Due to the use of non-woven or knitted rovings and in particular based on the use of ECR glass fibers with 1200 tex, 2400 tex or 4800 tex, it is possible to reduce the basis weight of the composites. In a preferred embodiment, therefore, the basis weight of the composite is at most 1000 g / m ² , preferably at most 700 g / m ² , such as a maximum of 500 g / m ² , for example a maximum of 300 g / m ² . The minimum film weight should be 200 g / m ² (eg with a glass fiber content of at most 50% by weight).

The composites according to the invention are characterized in that, with a reduced basis weight and reduced thickness, the mechanical properties, in particular strength values, are not impaired. Thus, tensile strength, modulus of elasticity and elongation value can be kept equal to conventional products, even if the basis weight is reduced by at least 20%, and preferably at least 25%, over a commercial woven or laid fiberglass mat product. Compared with conventional composites, it is possible to significantly reduce the thickness of the composite, e.g. by at least 30%, as at least 50%.

The composites according to the invention are processed according to the invention in composite materials. Composite materials according to the invention are those made from at least two layers of composite, at least one of these layers being a composite according to the invention.

It is preferred that in the composite material according to the invention, the fiber orientation of the fibers of the filaments of the rovings are angularly offset in their main direction in the layers, in particular angularly offset by 45 ° and / or 90 ° in order to obtain multi-directional loop structures in the composite material.

It is therefore possible to achieve a scalable multi-layer structure in the composite, wherein a load-oriented fiber orientation in the composite material is possible. That is, the load-oriented fiber orientation is possible in that the composite material, in which the fibers of the filaments of the rovings are angularly offset in their main extension device in different positions, is built to accommodate the desired loads can.

In particular, when using ECR glass fibers, the composites and composite materials according to the invention are distinguished by lower basis weights and better strength values. As a result, weight reductions compared to conventional composites and composites, which are formed with mats or fabrics as reinforcing fibers, can be achieved.

It is preferred that the composites and composites are present in one component or as part of a component. At least one layer of a composite according to the invention or a composite material according to the invention, such as a layered composite material, is present in the component according to the invention. The composite according to the invention and / or the composite material according to the invention preferably form the outer layer.

In this case, the component according to the invention with at least one outer layer made of a composite according to the invention or an outer layer made of a composite material according to the invention with a supporting structure is preferred. in particular a support core. Support structure and support core may be formed with conventional materials in the usual manner. For example, this component may be a sandwich plate, with the support core preferably being a honeycomb core. Other embodiments are possible.

The composites of the invention e.g. in the form of composites or components can be used in various fields. An area is e.g. the vehicle construction. It is possible to use the composites, composite materials or components for truck bodies according to the invention, such as e.g. as a box body in refrigerated vehicles or in freight vehicles. Furthermore, corresponding components, composite materials or composites can be used as roof elements, body in side walls, front elements, rear parts or doors. In the motorhome or caravan area, suitable composites, composite materials or components can be used as sidewalls or in interior fitting areas.

Other applications include shipbuilding and boatbuilding. Here, the composites, composites or components of the invention can be used in interior design. Furthermore, the composites, composites or components according to the invention find application in battery housings or as a carrier for electrodes. Also in the construction sector such. For door leaves or in prefabricated areas, the corresponding components composites or composite materials can be used. Further possibilities according to the invention include housing, e.g. in wind turbines but also heat storage or tanks in industrial construction.

The components can be produced from a plurality of layers of the composite according to the invention, in which the fibers absorb the applied forces in the direction of the laid fibers. These components can then be encapsulated with respect to geometry completion with thermoplastics.

The composites, composites or components according to the invention are thus versatile.

In a further aspect, the present application is directed to a process for the preparation of the composite according to the invention. The method comprises the steps of: providing the glass fiber rovings; Applying the thermoplastic to the glass fiber rovings, preferably by means of an extruder; Rolling the thermoplastic-coated glass fiber rovings to distribute the thermoplastic and to (end) spread the roving into single filaments to obtain a precursor; and curing the rolled precursor to obtain a composite of the invention. The glass fiber rovings are, in particular, endless fiber rovings. In one embodiment, the single glass fiber roving can be rolled even before the addition of the thermoplastic in order to achieve spreading of the roving in single filaments / individual fibers. The spreading step after the addition of the thermoplastic then allows a final spreading thereof, e.g. in the individual fibers.

The composite produced is particularly preferably an endless composite.

The method for producing a composite material according to the invention comprises the production of the composite as stated above. In addition, the at least one further layer of the composite material is placed in the form of plates on the precursor or on already cured composite and then hardened the precursor or the composite with the applied plates. This makes it possible to use multidirectional structures, e.g. to obtain as a homogeneous multidirectional clutch. In the production of the fiber composite material can be used as a binder matrix material or other suitable curable binder.

According to the invention it is possible, the rovings directly as unidirectional To achieve filament templates by appropriately unwinding the filament rovings of coils. Another step for weaving or knitting is not necessary.

With the process of the invention, drapability, i. the spherical deformability can be adjusted to the contour of a three-dimensional surface adjustable.

Finally, a device is described for producing the composites according to the invention. The device comprises a device for the parallel laying of Glasfaserrovings. The glass fiber rovings are preferably placed directly from the coil. The laid rovings are optionally spread by means of rollers or calenders. Subsequently, the matrix material - the thermoplastic - is applied with a corresponding device. This is usually done with an extruder. After the extruder, the spread roving and matrix precursor is removed by means of rolls and calenders, e.g. with hot rollers, shaped, the roving further spread and cured the matrix material to obtain composites according to the invention with splayed individual fibers.

In the following the invention will be explained in more detail by means of examples without being limited thereto.

example 1

The product used is the product Vetrolite 2.2 (Vetroresina LLC, USA). This is a composite material with a composite of PP and glass fiber mat with an E-glass.

• Als Roving wurde ECR-Glas (2400 tex), das als Roving auf Spulen vorliegt, verwendet. Die Rovings wurden aus einem Spulengatter von den Spulen drehungsfrei, ohne große Spannung abgezogen und nebeneinander parallel abgelegt. Dabei werden möglichst die angestrebte Ausbreitung der Fasern und das gewünschte Flächengewicht an Fasern bereits eingestellt. Durch Umlenkungen an mehreren Walzen werden die Rovings parallel ausgerichtet und gespreizt. Im Heißkalander erfolgt die endgültige Spreizung der Filamente und gleichzeitig die Beschichtung und Ummantelung mit den Thermoplasten (z. B. mit Hilfe eines Extruders), z. B. mit Moplen EP 300M Lyondell Basell, Polymers (Schmelzindex 7,0 g/10 min bei 230°C(2.16 kg; Zugfestigkeit 21.5 MPa).

The composite material according to the invention with a composite according to the invention was produced as follows:

• The roving used was ECR glass (2400 tex), which is present as coils roving. The rovings were taken from a creel of the bobbins without rotation, removed without great tension and placed side by side in parallel. As far as possible, the desired spread of the fibers and the desired basis weight of fibers are already set. By deflections on several rollers, the rovings are aligned and spread parallel. In the hot calender, the final spreading of the filaments takes place and at the same time the coating and coating with the thermoplastics (eg with the aid of an extruder), eg. With Moplen EP 300M Lyondell Basell, Polymers (melt index 7.0 g / 10 min at 230 ° C (2.16 kg, tensile strength 21.5 MPa).

Table 1 shows the properties of the composite material according to the invention with 2 layers and of vetroresina. <b> Table 1 </ b> product according to the invention vetroresina Thickness (mm) ISO 16012 1 2.2 Basis weight (g / m ² ) ISO 16012 700 2700 Tensile strength (MPa) DIN EN ISO 527-4 > 200 58 Modulus of elasticity (MPa) DIN EN ISO 527-4 > 10,000 5300 Elongation value (%) DIN EN ISO 527-4 > 2 1.3

As is apparent from Table 1, the 2-layer composite of the present invention exhibits improved tensile strength and modulus of elasticity as compared with the prior art at a much smaller thickness and substantially lower basis weight. Also, the strain value is opposite improved the comparison.

It is thus possible according to the invention to provide composites, composites, as well as components whose mechanical properties are at least equivalent to prior art products, wherein the thickness and the basis weight are reduced, so that on the one hand costs can be reduced and on the other hand also a weight reduction and eg In the vehicle area a fuel saving is possible.

Example 2

As described in Example 1, composites are produced, composite 1 being obtained without subsequent spreading of the glass fibers after the thermoplastic coating, composite 2 according to the invention subjected to subsequent further spreading (thickness of the composite: 0.28 mm, basis weight: 350 g / m ²⁾ ). <b> Table 2 </ b> Modulus tensile strenght strain value Composite 1 14645 MPa 180 MPa 2.64% Composite 2 28041 MPa 392 MPa 1.51%

It thus appears that the spread after application of the thermoplastic significantly improves the mechanical properties.

Example 3

The further processing of composites according to the invention into a multidirectional jelly structure is carried out by placing the corresponding prefabricated panels in the required laying angle on a (0 °) continuous web running in the direction of production. The multidirectional scrim is in turn consolidated by means of hot calender rolls to form a homogeneous scrim.

Because of the stretched and oriented glass fibers in the multidirectional support structures, fiber composite applications can benefit from exploiting the fiber specific properties of the high performance fibers in the desired direction.

Claims (16)

Composite with glass fiber roving and a thermoplastic matrix wherein the glass fibers of the roving run in a main direction, characterized in that the roving in the composite is not woven, braided or knitted and the roving was spread at least after the addition of the thermoplastic in single glass fibers. Composite according to claim 1, characterized in that the roving is made of ECR glass, in particular an ECR glass with 2400 and 4800 TEX. Composite according to one of the preceding claims, characterized in that the thermoplastic is selected from polyolefin, in particular polyethylene and polypropylene, polyamide, polylactate, polymethyl methacrylate, polycarbonate, polyethylene terephthalate, polystyrene, polyether ketone and polyvinyl chloride, in particular of polyolefin or polyamide. Composite according to one of the preceding claims, characterized in that this maximum 1 mm, such as up to 0.7 mm, in particular up to 0.5 mm, z. B. up to 0.3 mm thick. Composite according to one of the preceding claims, characterized in that it has a basis weight of at most 1000 g / m ² , preferably at least at most 700 g / m ² , and / or the minimum basis weight of at least 200 g / m ² , such as at least 300 g / m ² , is. Composite according to one of the preceding claims, wherein at least two glass fiber rovings preferably present in parallel running in the composite. Composite of at least two layers of composite, wherein at least one of these layers is a composite according to one of claims 1 to 6. A composite material according to claim 7, wherein the fibers of the rovings are angularly offset in their main extension direction in the layers, in particular angularly offset by 45 ° and / or 90 °. Component with at least one layer of a composite according to one of claims 1 to 6 or with a composite material according to one of claims 7 or 8, such as a layer composite material, in particular wherein the composite according to the invention or the composite material according to the invention forms the outer layer. Component according to claim 9 having at least one outer layer of a composite according to any one of claims 1 to 6 or an outer layer of a composite material according to any one of claims 7 or 8 and a support structure, in particular a support core. Component according to one of claims 9 or 10 in the form of a sandwich plate, in particular with a honeycomb core as a support core. Use of a composite according to one of claims 1 to 6 or a composite material according to one of claims 7 or 8 or a component according to one of claims 9 to 11 in the vehicle sector. Process for producing a composite according to one of Claims 1 to 6, comprising the steps: Providing at least one glass fiber roving, preferably at least two glass fiber rovings, these optionally being substantially parallel; - Applying the thermoplastic to the glass fiber rovings, preferably by means of an extruder; - Rolling the thermoplastic-coated fiber roving to distribute the thermoplastic and to spread the roving into individual fibers to obtain a precursor; Hardening the rolled precursor to obtain a composite according to any one of claims 1 to 6, wherein the glass fiber roving is used in particular as continuous fiber roving. A method according to claim 13, characterized in that the composite produced is an endless composite. Method according to one of claims 13 or 14, characterized in that the glass fiber rovings are spread prior to application of the thermoplastic in individual filaments. A process for producing a composite material according to any one of claims 7 to 8, characterized in that the at least one further layer of the composite is placed in the form of plates on the precursor and then the precursor is cured with the plates.